Integrative echocardiographic assessment of post-operative obstruction severity and restenosis after balloon valvuloplasty in 81 dogs with pulmonary stenosis.

INTRODUCTION/OBJECTIVES: Pulmonary stenosis (PS) is a congenital defect in the dog that is managed with balloon valvuloplasty (BV). Obstruction severity is routinely assessed using transthoracic echocardiography. The objectives of this study were to describe the short-term changes and long-term restenosis by retrospectively evaluating flow-dependent and flow-independent echocardiographic variables for dogs with PS after BV. ANIMALS, MATERIALS, AND METHODS: Medical records and stored echocardiographic images were reviewed from dogs that received BV for PS. The following echocardiographic variables were measured or calculated: maximum systolic ejection velocity (VmaxPV) and velocity-derived maximal pressure gradient (PV maxPG) across the pulmonary valve; ratio of aortic to pulmonary velocity time integral (VTIAV/VTIPV); ratio of aortic to pulmonary maximal velocity. RESULTS: Eighty-one dogs with PS that had a BV were included. Each of these dogs had pulmonary obstruction severity assessed in at least three timepoints. Forty-nine dogs had at least one additional examination performed, the last of which occurred a median of 504 days after the BV. Echocardiographic variables at the first follow-up had increased by a clinically relevant quantity in 20-34% of the dogs when comparing to the immediate post-BV examination. The last follow-up examination identified valve restenosis in 18-38% of the dogs in this study. Valve type and pre-BV obstruction severity did not have a significant effect (P > 0.1). CONCLUSIONS: For the assessment of BV efficacy, the immediate post-BV echocardiogram may not be as useful as the first follow-up examination several months later. Pulmonary restenosis after BV may be more prevalent than previously reported.

Right coronary artery to left ventricle coronary cameral fistula in a cat.

A six-month-old female intact domestic shorthair cat was presented for evaluation of a loud heart murmur. Transthoracic echocardiography revealed dilation of the left ventricle secondary to an abnormal vessel shunting blood into the left ventricular outflow tract at a high velocity during diastole. Multidetector computed tomography angiography revealed a coronary cameral fistula that originated at the right coronary artery, encircled the heart, and then terminated into the left ventricular outflow tract. This case report documents the first known case of a coronary cameral fistula in a cat. Multimodal imaging was an essential aspect to diagnosing the congenital lesion in this case.

Hybrid balloon valvuloplasty for management of severe mitral stenosis in four symptomatic, adult dogs.

Four adult dogs weighing <10 kg presented for the evaluation of severe mitral valve stenosis with clinical signs. Owing to the size of the dogs, a hybrid surgical and interventional approach was utilized for balloon valvuloplasty. A left lateral thoracotomy was performed to allow direct entry through the left atrial wall. Transesophageal echocardiography was utilized for the entirety of the procedure in all dogs, and fluoroscopy was additionally used in two dogs. One dog had mild to moderate intra-operative bleeding from the left atrial wall during the procedure, but no other intra-operative complications were observed. No dogs developed a clinically relevant amount of worsened mitral regurgitation. Based on mitral leaflet mobility and transmitral flow profiles, there was perceived improvement in all four dogs. One dog died 6 h after extubation due to respiratory arrest. The remaining dogs survived to discharge and had resolution of clinical signs at home and discontinuation of heart failure medications. One dog died of an unknown cause at five months and another developed atrial fibrillation, and the owners elected to euthanize at ten months after the procedure. One dog continues to do well six months after the procedure as of the time of this writing. Hybrid balloon valvuloplasty can be a viable management option for small breed dogs with severe mitral stenosis exhibiting clinical signs, and both transesophageal echocardiography and fluoroscopy can be used intra-operatively to assist in successful procedural outcomes.

Transient high-grade second-degree atrioventricular block secondary to transvenous atrial septal defect occlusion in a dog.

A 1.2-year-old male-intact Standard Poodle underwent transvenous placement of an Amplazter™ atrial septal occluder for correction of a large secundum atrial septal defect. Thirty-six hours post-operatively, the dog developed high-grade Mobitz type II second-degree atrioventricular block, which resolved with time and corticosteroid administration by 12 days after the procedure. This case report outlines the observation, treatment, and resolution of high-grade Mobitz type II second-degree atrioventricular block, a known complication of atrial septal occluder placement in humans, not previously reported in veterinary literature.

Long-term relief of obstruction in a dog with double-chambered right ventricle using combined cutting balloon and high-pressure balloon dilation.

A 4-month-old intact female Golden Retriever dog was diagnosed with double-chambered right ventricle (DCRV) without infundibular stenosis, tricuspid valve dysplasia, and subsequent severe right atrial enlargement and was referred for combined cutting balloon and high-pressure balloon dilation. On presentation, these diagnoses were confirmed, and the peak systolic pressure gradient across the DCRV obstructive lesion assessed by continuous wave Doppler interrogation was 80 mm Hg. The obstructive lesion within the mid-right ventricle had a diameter of 6 mm through which blood flowed from the proximal right ventricular (RV) chamber to the distal RV chamber. The following day, general anesthesia was induced, and a minimally invasive balloon dilation was performed. A cutting balloon was inflated across the mid-RV obstructive lesion, followed by an inflation of a high-pressure balloon across this lesion. The high-pressure balloon catheter that was used had a diameter roughly 1.5 times the diameter of the pulmonary annulus. The following day, echocardiographic evaluation of the patient revealed a peak systolic pressure gradient across the DCRV obstructive lesion of 16 mm Hg, with a RV diameter at the level of obstruction of 11 mm. Twelve months later, the dog remains asymptomatic, right atrial size has decreased, and has a peak systolic pressure gradient across the DCRV lesion of 20 mm Hg.

Characterization of arrhythmias, evaluation of cardiac biomarkers and their association with survival in calves suffering from foot-and-mouth disease.

INTRODUCTION: Foot-and-mouth disease (FMD) causes mortality in calves due to myocarditis; however, the effects of FMD virus on cardiac arrhythmogenesis and Purkinje cells are unknown. Identifying diagnostic and prognostic markers in FMD-affected calves may be useful in disease management in the endemic countries. MATERIALS AND METHODS: A total of 81 FMD-affected calves were prospectively monitored till death or recovery. Foot-and-mouth disease was diagnosed by serology and reverse transcriptase-polymerase chain reaction (RT-PCR). Electrocardiography was recorded and serum cardiac biomarkers were measured. Histopathological examination of the ventricular myocardium was carried out in the calves that died of FMD (n = 33). Apparently healthy calves (n = 15) served as control. RESULTS: Serology and RT-PCR consistently revealed that the FMD was caused by serotype O virus. Arrhythmias occurred in 62 of 81 (76.5%) FMD-affected calves, of which, ventricular premature complexes (VPCs) were the most common type (22%). The combined mortality rate due to ventricular tachycardia, polymorphic VPCs, and atrial fibrillation was 27.6%. Receiver operating characteristic curve analysis revealed that cardiac troponin I (cTnI) concentrations of ≥1.3 ng/mL were diagnostic of myocarditis with a sensitivity and specificity of 90% and 100%, respectively. Similarly, serum cTnI concentrations of <6.4 ng/mL were a good predictor of survival [odds ratio of 263; 95% confidence interval: 29-2371]. Histopathology of the myocardium revealed hyaline degeneration, necrosis, edema, mononuclear cell infiltration, and disruption by fibroblasts. Atrophy of the Purkinje cells was also present. CONCLUSIONS: FMD induces cardiac arrhythmias and Purkinje cell pathology in the calf. Portable ECG coupled with assay of serum cTnI would help in predicting survival in FMD-affected calves.

Repeat balloon valvuloplasty for dogs with recurrent or persistent pulmonary stenosis.

INTRODUCTION/OBJECTIVES: Pulmonary stenosis (PS) is a common congenital defect in the dog. Severe valvar PS can be treated with balloon valvuloplasty (BV) to reduce obstruction severity and improve clinical signs. Repeat BV is often unnecessary, as restenosis is uncommon. Repeated pulmonary BV in people is generally successful and safe, but outcomes in dogs with recurrent or persistent stenosis have not been reported. The objectives of this study were to retrospectively evaluate outcomes of repeat BV in dogs. ANIMALS, MATERIALS, AND METHODS: Medical records and stored echocardiographic images were reviewed from dogs that received repeat BV for pulmonary valvar restenosis or persistent stenosis. Echocardiographic variables included maximum systolic ejection velocity (PVmax), velocity-derived maximal pressure gradient (PGmax) and velocity time integral (VTI) across the pulmonary valve, and ratios of pulmonic to aortic maximum velocity (PVmax/AVmax) and VTI (VTIPV/VTIAV). RESULTS: Twenty-three dogs were included; one underwent three BV procedures. The median time between BV procedures was 18.3 months (interquartile range, 6.3-43.6). One dog died during repeat BV, but no others experienced adverse effects. Reductions in PVmax, PGmax, and VTIPV after initial and repeat BV were 1.85 m/s, 76.2 mmHg, and 44.7 cm and 1.33 m/s, 55.6 mmHg, and 30.2 cm, respectively (all p < 0.01). Differences between pre-BV and post-BV PVmax, PGmax, VTIPV, PVmax/AVmax, and VTIPV/VTIAV were not different comparing initial to repeat BV (all p > 0.10). CONCLUSIONS: Repeat BV for recurrent or persistent PS is well tolerated and effective in a majority of dogs.

Transcatheter embolization of systemic-to-pulmonary artery fistulas in a dog using embolization coils and silk suture.

A 4-month-old intact female Cavalier King Charles spaniel presented for evaluation of a left, basilar continuous murmur. Transthoracic echocardiography suggested anomalous vessels around the main pulmonary artery, and computed tomography angiography revealed two systemic-to-pulmonary artery fistulas. Transcatheter embolization of these fistulas was achieved with a combination of embolization coils and silk suture threads delivered through a microcatheter.

Balloon valvuloplasty in a dog with congenital bicuspid aortic valve and supravalvar aortic stenosis (atypical Shone's complex).

An 8-month-old intact female pug was presented for evaluation and possible balloon valvuloplasty (BV) for severe aortic stenosis. A bicuspid, severely stenotic aortic valve of type 3 morphology with a supravalvar stenosis component was diagnosed, consistent with the diagnosis of atypical Shone's complex. There was severe concentric hypertrophy of the left ventricle, with increased echogenicity of the myocardium nearest to the endocardial border. Mild left atrial enlargement was observed. Selective angiography and transesophageal echocardiography revealed an enlarged and relatively tortuous ascending aorta. The changes to the ascending aorta and the anatomy of the lesion made retrograde access to the left ventricle challenging. Ultimately, BV was successful using a pediatric valvuloplasty balloon catheter and rapid right ventricular pacing, and the pressure gradient across the aortic valve was decreased by more than 50% compared with preoperative measurements. Although valvar aortic stenosis is rare in veterinary medicine, this report highlights the potential challenges and feasibility of BV for this disease.

Retrospective evaluation of notched QRS complexes in dogs: 85 cases.

INTRODUCTION: Notched QRS complexes on electrocardiography (ECG) have been described in veterinary and human reports, but little is known about this finding in veterinary patients. Therefore, the objectives of this study were to describe the signalment and cardiac disease diagnosis in dogs with notched QRS complexes, as well as to describe the specific leads and number of leads with notched QRS complexes on ECG. ANIMALS: Eighty-five dogs with notched QRS complexes of normal duration in at least one ECG lead. METHODS: Retrospective review of digitally stored ECGs and associated medical records of dogs with a recorded ECG as part of routine clinical evaluation. RESULTS: Age at time of ECG recording was 9.15 ± 3.38 years for the 85 dogs with notched QRS complexes in at least one ECG lead. The number of ECG leads with notched QRS complexes did not increase with age. Most dogs (69.4%) with notched QRS complexes had cardiac disease. The odds ratio of a dog having cardiac disease if more than one lead was identified with notched QRS complexes was 3.97. The most common cardiac disease identified was chronic atrioventricular valvular degeneration, and the majority of these dogs (80%) had two or less leads with notched QRS complexes. CONCLUSIONS: Dogs with and without cardiac disease can have notched QRS complexes. The likelihood of a dog having cardiac disease that has more than one ECG lead with notched QRS complexes is significant, and this should warrant diagnostic evaluation.

Double-outlet right ventricle with an intact interventricular septum and concurrent hypoplastic left ventricle in a calf.

A 3-day-old Hereford heifer calf presented for evaluation of lethargy and dyspnea, with persistent hypoxia despite supplemental oxygen therapy. A grade III/VI right apical systolic murmur was noted during cardiac auscultation. Echocardiography revealed a double-outlet right ventricle with an intact interventricular septum and concurrent hypoplastic left ventricle and tricuspid valve dysplasia. Post-mortem examination revealed additional congenital anomalies of ductus arteriosus, patent foramen ovale, and persistent left cranial vena cava. This report illustrates the use of echocardiographic images to diagnose a double-outlet right ventricle with an intact interventricular septum and a hypoplastic left ventricle in a calf.